Conditional — Some Areas
false sunflower (zones 4-9) has limited zone overlap with Wyoming (3a-5b). Only zones 4-5 in the state are suitable.
Your yard isn't the whole zone.
Wyoming spans zones 3a-5b, but your yard has its own microclimate — slope, trees, and low spots shift frost and sun across a single parcel. Enter your address and we'll score false sunflower against your land's actual soil, sun, and frost.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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Zone Comparison
False Sunflower Needs
- USDA Zones: 4-9
- Soil pH: 5 - 7.5
- Sun: Full Sun
- Drainage: well (dry spells)
- Frost-Free Days: 90+
Wyoming Has
- USDA Zones: 3a-5b
- Last Frost: May 10 - Jun 15
- First Frost: Aug 25 - Sep 25
- Annual Rainfall: 6-20 inches
- Common Soils: Sandy loam, Clay, Alkaline
Plant Zone Range (zones 4-9)
Preferred Soil pH
Plant data: USDA PLANTS Database / plant_species_v5.csv. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.
When to Plant False Sunflower in Wyoming
The frost window
Across Wyoming, the last spring frost clears between May 10 and Jun 15, and the first fall frost lands between Aug 25 and Sep 25 (NOAA Climate Normals 1991-2020). Counting from the latest last frost to the earliest first frost, that's a 71-day window you can count on — up to 138 days on a mild site in a kind year.
Frost tenderness
False Sunflower is frost-tender — its listed minimum temperature is 51.8°F (USDA PLANTS Database) — so set plants out after the last frost has cleared your local site, not the state's earliest date.
Timing tuned to sub-state frost dates — Lincoln County, not the statewide average.
Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: USDA PLANTS Database. Your site's own frost dates can run earlier or later than the state range — a parcel report pins them down.
Growing Season Fit
Zone compatibility says you can survive winter here. Whether the growing season is long enough — and warm enough — is a different question.
Frost-free days
False Sunflower wants 90+ frost-free days; a typical Wyoming site sees ~170 (NOAA Climate Normals). That leaves comfortable headroom for succession planting.
Climate aggregates derive from USDA NRCS county-level hardiness data + Cornell CALS Extension GDD-by-region tables + MSU Extension chill-hours-by-zone (1991-2020 NOAA Climate Normals baseline).
Soil + Drainage Fit
False Sunflower likes near-neutral soil (pH 5-7.5). That's the common-ground band across Wyoming's sandy loam and clay — a soil test confirms it for your site. Drainage matters: this plant wants well (dry spells). If your Wyoming site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
Your land, not the state average
Wyoming's soils run mostly loam, but SSURGO maps the series, texture, and drainage under your exact parcel — that map unit, not the state average, decides how false sunflower performs.
Check your parcel → Source: USDA NRCS SSURGO.
Plant pH and drainage requirements from USDA PLANTS Database. Wyoming soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
False Sunflower in Wyoming — Quick Answer
- Verdict: Conditional — Some Areas
- Plant Zones: 4-9 (USDA PLANTS Database)
- State Zones: 3a-5b (USDA ARS PHZM 2023)
- Growing Season: May 10 - Jun 15 to Aug 25 - Sep 25 (NOAA Climate Normals)
What Else to Consider
Zone compatibility tells you about winter cold survival — but Wyoming growers also need to think about:
Extremely short growing season (60-90 frost-free days)
At 60-90 frost-free days, a greenhouse or high tunnel isn't optional equipment — it's where the season actually happens.
Very low rainfall requires irrigation
Drip irrigation under mulch makes scarce water go the distance — build the system before the first bed.
Persistent high winds desiccate and damage plants
Windbreaks first, plants second — a sheltered bed loses a fraction of the moisture an exposed one does.
Growing false sunflower here specifically
False Sunflower sends deep roots and rates to zones 4–9, but much of Wyoming sits on slow-draining, restrictive ground (SSURGO hydrologic group D) that forks and stunts them.
Loosen a deep, stone-free bed for false sunflower and break any compacted or hardpan layer before planting. How to handle it →
Timing shifts within Wyoming
Wyoming isn't one climate. In Lincoln County, the last hard freeze (28°F) holds until about May 23 — roughly 25 days later than the recorded state median — so plant false sunflower to your county's window, not the statewide date.
County last-freeze dates: NOAA/PRISM Climate Normals 1991-2020, 28°F threshold (earlier than the folk 32°F "last frost"). A parcel report resolves your address's own frost dates.
Pollinator + Wildlife Value
False Sunflower draws pollinators (high value, USDA PLANTS Database). Planting it near vegetable beds can lift fruit set on neighboring crops.
Recommended False Sunflower Varieties for Wyoming
Wyoming publishes no state variety trial for false sunflower, so we won't invent a "best for Wyoming" list. Choose types rated to your USDA hardiness zone (3a-5b), and confirm winter survival and drainage against your own parcel.
Wyoming Cooperative Extension
For Wyoming-specific cultivar recommendations, planting calendars, and pest pressure for false sunflower, the canonical source is University of Wyoming Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is False Sunflower native to Wyoming?
False Sunflower is native to parts of the Lower 48, but the USDA PLANTS Database (accessed 2026-07-01) does not document a native range in Wyoming. It can still earn a place in a Wyoming garden — the zone comparison above tells you whether it will thrive.
Looking for plants that belong here? The Wyoming growing guide lists USDA-documented natives for the state.
Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.
Common Questions About Growing False Sunflower in Wyoming
When can I plant False Sunflower in Wyoming?
Wyoming's last spring frost clears between May 10 and Jun 15, and the first fall frost lands between Aug 25 and Sep 25 (NOAA Climate Normals 1991-2020). False Sunflower is frost-tender — its listed minimum temperature is 51.8°F (USDA PLANTS Database) — so wait until the last frost has cleared your specific site before planting out.
What hardiness zone is False Sunflower grown in across Wyoming?
Wyoming spans USDA hardiness zones 3a-5b (USDA ARS PHZM 2023). False Sunflower carries a range of zones 4-9, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical Wyoming site have?
A typical Wyoming site sees ~170 frost-free days per year (derived from NOAA Climate Normals 1991-2020). False Sunflower needs 90+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date. In cooler counties like Lincoln, the freeze-free season runs shorter than the state average, so verify your own county's window.
Is False Sunflower native to Wyoming?
False Sunflower is native to parts of the Lower 48, but the USDA PLANTS Database (accessed 2026-07-01) does not document a native range in Wyoming. It can still earn a place in a Wyoming garden — the zone comparison above tells you whether it will thrive.
How should I amend the soil for False Sunflower in Wyoming?
False Sunflower prefers pH 5-7.5 and well (dry spells) drainage (USDA PLANTS Database). That sits in the common-ground band across Wyoming soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.
Will False Sunflower actually grow on my specific land in Wyoming?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores false sunflower against your address's exact soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.
Check your specific parcel in Wyoming
State-level data is a sketch. Your Growable Ground report scores false sunflower against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Analysis by the Growable Ground research team, grounded in USDA PLANTS, USDA NRCS SSURGO, NOAA Climate Normals (1991-2020), and named Cooperative Extension sources. How we know →